Robert Yee

Opportunistic Lung Infection Due to Pittsburgh Pneumonia Agent

Eight immunosuppressed patients had pneumonia due to Pittsburgh Pneumonia Agent (PPA), a gram-negative, weakly acid-fast bacterium cultivatable only in embryonated eggs and guinea pigs and distinct from Legionella pneumophila. The diagnosis was established by isolation of the agent from lung or visualization of the organism in lung tissue. The clinical presentations, radiographic abnormalities and pathology were not specific. The most consistent feature associated with the disease was the recent institution of daily high-dose corticosteriod therapy in all patients. Five of the eight patients died despite broad-spectrum antibiotic and antituberculous therapy. Anti-microbial activity against PPA was demonstrated for sulfamethoxazole combined with trimethoprim, for rifampin and for erythromycin with an egg-protection assay. Serologic studies with an indirect fluorescent-antibody technic suggested that seroconversion or high titers may be a sensitive test for PPA disease. PPA appears to be a newly recognized cause of life-threatening bacterial pneumonia in immunosupressed patients.

Political priority of global oral health: an analysis of reasons for international neglect

Global Oral Health suffers from a lack of political attention, particularly in low- and middle-income countries. This paper analyses the reasons for this political neglect through the lens of four areas of political power: the power of the ideas, the power of the issue, the power of the actors, and the power of the political context (using a modified Political Power Framework by Shiffman and Smith. Lancet370 [2007] 1370). The analysis reveals that political priority for global oral health is low, resulting from a set of complex issues deeply rooted in the current global oral health sector, its stakeholders and their remit, the lack of coherence and coalescence; as well as the lack of agreement on the problem, its portrayal and possible solutions. The shortcomings and weaknesses demonstrated in the analysis range from rather basic matters, such as defining the issue in an agreed way, to complex and multi-levelled issues concerning appropriate data collection and agreement on adequate solutions. The political priority of Global Oral Health can only be improved by addressing the underlying reasons that resulted in the wide disconnection between the international health discourse and the small sector of Global Oral Health. We hope that this analysis may serve as a starting point for a long overdue, broad and candid international analysis of political, social, cultural, communication, financial and other factors related to better prioritisation of oral health. Without such an analysis and the resulting concerted action the inequities in Global Oral Health will grow and increasingly impact on health systems, development and, most importantly, human lives.

Incidence and Impact of Painful Exacerbations in a Cohort with Post-treatment Persistent Endodontic Lesions

INTRODUCTION Painful exacerbations of persistent periapical lesions have unknown incidence and impact on quality of life. This study examined the incidence and impact of painful exacerbations and evaluated potential predictive factors of pain associated with root-filled teeth with persistent lesions after root canal treatment. METHODS Patients from a university hospital clinic were screened to identify root-filled teeth with periapical lesions at time of treatment and not resolved at least 4 years later. A clinical and radiographic examination and questionnaire survey were conducted. Patient and treatment characteristics and details of pain experience were studied. Statistical analysis was carried out by using SPSS (version 18). RESULTS One hundred twenty-seven patients with 185 persistent lesions were recruited. Median age of patients at recruitment was 56 years (range, 21-82 years). Median time since treatment was 5 years (range, 4-38 years). Overall incidence of flare-up (requiring an unscheduled dental visit) was only 5.8% 20 years after treatment. Less severe pain was more frequent, with a combined incidence of 45% pain at 20 years after treatment. Female patients (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.2-6.0; P < .05), treatment involving a mandibular molar or maxillary premolar (OR, 3.7; 95% CI, 1.6-8.6; P < .05), and preoperative pain (OR, 2.9; 95% CI, 1.3-6.7; P < .05) were significantly associated with pain after treatment. The most commonly affected activities during painful exacerbations were eating and tooth brushing, with minimal impact on daily living. CONCLUSIONS The risk of flare-up among persistent lesions was very low. A lower degree of pain was more common, but generally with minimal impact on daily activities.

Lesion Progression in Post-treatment Persistent Endodontic Lesions

INTRODUCTION Radiographic lesions related to root-filled teeth may persist for long periods after treatment and are considered to indicate failure of initial treatment. Persistent lesions are found in a proportion of cases, but information on lesion progression is lacking. This study examined the incidence of lesion improvement, remaining unchanged, and deterioration among persistent lesions in a group of patients recruited from a university-based clinic and identified potential predictors for lesion progression. METHODS Patients of a university clinic with persistent endodontic lesions at least 4 years since treatment and with original treatment radiographs available were recruited with informed consent. Data were obtained by interview and from dental records and clinical and radiographic examinations. Univariate and multivariate statistical analyses were carried out by using SPSS (version 19). RESULTS One hundred fifty-one persistent lesions were identified in 114 patients. A majority of the lesions (107, 70.9%) received treatment between 4 and 5 years prior. Eighty-six lesions (57.0%) improved, 18 (11.9%) remained unchanged, and 47 (31.1%) deteriorated since treatment. Potential predictors for lesions that did not improve included recall lesion size, pain on biting at recall examination, history of a postobturation flare-up, and a non-ideal root-filling length (P < .05). Lesions that had persisted for a longer period appeared less likely to be improving (relative risk, 1.038; 95% confidence interval, 1.000-1.077). CONCLUSIONS A specific time interval alone should not be used to conclude that a lesion will not resolve without intervention. This study identified several clinical factors that are associated with deteriorating persistent lesions, which should aid in identifying lesions that require further intervention.

Identification of Caries Risk Determinants in Toddlers: Results of the GUSTO Birth Cohort Study

The aim of this study was to identify risk determinants leading to early childhood caries (ECC) and visible plaque (VP) in toddlers. Data for mother-child pairs participating in the Growing Up in Singapore towards Healthy Outcomes (GUSTO) birth cohort were collected from pregnancy to toddlerhood. Oral examinations were performed in 543 children during their clinic visit at 24 months to detect ECC and VP. Following logistic regression, ECC and VP were jointly regressed as primary and secondary outcomes, respectively, using the bivariate probit model. The ECC prevalence was 17.8% at 2 years of age, with 7.3% of children having a VP score >1. ECC was associated with nighttime breastfeeding (3 weeks) and biological factors, including Indian ethnicity (lower ECC rate), higher maternal childbearing age and existing health conditions, maternal plasma folate <6 ng/mL, child BMI, and the plaque index, while VP was associated with psychobehavioral factors, including the frequency of dental visits, brushing frequency, lower parental perceived importance of baby teeth, and weaning onto solids. Interestingly, although a higher frequency of dental visits and toothbrushing were associated with lower plaque accumulation, they were associated with increased ECC risk, suggesting that these established caries-risk factors may be a consequence rather than the cause of ECC. In conclusion, Indian toddlers may be less susceptible to ECC, compared to Chinese and Malay toddlers. The study also highlights a problem-driven utilization pattern of dental services (care sought for treatment) in Singapore, in contrast to the prevention-driven approach (care sought to prevent disease) in Western countries.

Oral health status and complete denture status of independent-living Singaporean elderly residing in a community home

AIM Past studies have examined the oral health status of elderly Singaporean adults residing in long term care facilities and living in residential housing but no oral health research has been conducted on elderly Singaporeans residing in community homes. The aim of this paper is to report on the oral health status and complete denture status of a group of free living (community dwelling) elderly in Singapore from the AWWA Community Home for Senior Citizens, and investigate the relation between the clinical findings and demographic data. MATERIALS AND METHODS This research used a cross-sectional design and was conducted in the month of December 2011. Consenting residents of the AWWA home who were over the age of 60 participated in this study. Sampling strategy was census. Two calibrated interviewers collected demographic information from the participants and four calibrated dentists conducted extra-oral and intra-oral soft tissue examinations along with assessment of dentition, periodontal and denture status. STATISTICAL ANALYSIS All data were input into Microsoft Excel 2010(™) and analysed in SPSS 21.0(™). Descriptive analysis and bivariate analysis were performed on the demographic factors and other variables of interest. The Spearman׳s test, Mann-Whitney U and Chi-Square test were used to examine the correlation between the clinical findings and age, gender and education level respectively. RESULTS Among the 70 participants, two subjects (2.9%) had complete dentition, 34 (48.6%) were partially dentate, and 34 (48.6%) had no teeth. The mean number of teeth among the partially dentate participants was 11.28 while the mean number of anterior, posterior and total occlusal contacts were 1.61, 2.17 and 3.78 respectively. The mean number of decayed teeth (DT) and filled teeth (FT) were 2.81 and 0.25, giving a mean DFT score of 3.06. The mean Root Caries Index was 0.13. Periodontal examination revealed that only 5 (13.9%) individuals had healthy periodontal tissues, while 2 (5.6%) had the highest score of 1, 9 (25.0%) had the highest score of 2, 11 (30.6%) had the highest score of 3 and 7 (19.4%) had the highest score of 4. Amongst the partially dentate, 14 had dentures and 20 had none. There were 34 edentulous participants and 23 had at least one denture while 11 did not have any complete dentures. The most frequent unsatisfactory finding for complete dentures was inadequate retention of the mandibular dentures. When the dentures were grouped into those that were satisfactory and those that had at least one unsatisfactory factor, 11 of the 26 maxillary dentures and 17 of the 23 mandibular dentures fell to the latter category. Analysis revealed that there was a correlation between age and the number of teeth with a correlation coefficient of -0.43 (p=0.01) and age with the mean DFT, -0.33 (p=0.05). CONCLUSION The findings of this study revealed a high treatment need for this group of elderly.

Risk Score Algorithm for Treatment of Persistent Apical Periodontitis

Persistent apical periodontitis related to a nonvital tooth that does not resolve following root canal treatment may be compatible with health and may not require further intervention. This research aimed to develop a Deterioration Risk Score (DRS) to differentiate lesions requiring further intervention from lesions likely to be compatible with health. In this cross-sectional study, patient records (2003-2008) were screened for root-filled teeth with periapical radiolucency visible on periapical radiographs taken at treatment and at recruitment at least 4 yr later. The final sample consisted of 228 lesions in 182 patients. Potential demographic and treatment risk factors were screened against 3 categorical outcomes (improved/unchanged/deteriorated), and a multivariate independent multinomial probit regression model was built. A 5-level DRS was constructed by summing values of adjusted regression coefficients in the model, based on predicted probabilities of deterioration. Most lesions (127, 55.7%) had improved over time, while 32 (14.0%) remained unchanged, and 69 (30.3%) had deteriorated. Significant predictors of deterioration were as follows: time since treatment (relative risk [RR]: 1.11, 95% confidence interval [CI]: 1.01-1.22, p = .030, rounded beta value = 1, for every year increase after 4 yr), current pain (RR: 3.79, 95% CI: 1.48-9.70, p = .005, rounded beta value = 13), sinus tract present (RR: 4.13, 95% CI: 1.11-15.29, p = .034, rounded beta value = 14), and lesion size (RR: 7.20, 95% CI: 3.70-14.02, p < .001, rounded beta value = 20). Persistent apical periodontitis with DRS <15 represented very low risk; 15-20, low risk; 21-30, moderate risk; 31-40, high risk; and >40, very high risk. DRS could help the clinician identify persistent apical periodontitis at low risk for deterioration, and it would not require intervention. When validated, this tool could reduce the risk of overtreatment and contribute toward targeted care and better efficiency in the timely management of disease.

Adult perceptions of dental fluorosis and select dental conditions-an Asian perspective.

OBJECTIVE To compare lay peoples perceptions with regard to various levels of dental fluorosis and select dental defects versus normal dentition. METHODS Adults rated digitally created photographs made showing lips (without retraction) and teeth depicting the following conditions: no apparent aesthetic defects (normal, Thylstrup- Fejerskov score 0 - TF0), 6 levels of fluorosis (TF1-6), carious lesions (two cavitated and one noncavitated), malocclusions (Class II, Class III, anterior open bite and greater spacing), extrinsic staining and an incisal chip. The photographs were displayed on colour-calibrated iPads(™) . Participants used a self-administered questionnaire to rate their perceptions on (Item 1) how normal teeth were, (Item 2) how attractive the teeth were, (Item 3) need to seek correction of teeth, (Item 4) how well the person took care of their teeth and (Item 5) whether the person was born like this. Data from Item 5 were excluded due to low reliability. RESULTS Ratings for Item 1 showed that TF1-4 was similar or significantly better than TF0. For Item 2, TF1 and TF4 were significantly better than TF0, with TF2 and TF3 being similar. For Item 3, there was significantly lower need to seek correction with TF2 and TF4 versus TF0, whereas TF1 and TF3 were similar to TF0. TF5 and TF6 were rated significantly lower than TF0 for Item 1 and Item 2, and significantly higher rating for Item 3 (need to seek correction). Ratings for Item 4 were similar, with TF1, TF2 and TF4 being rated significantly higher than TF0, and TF5 and TF6 being rated lower. Cavitated caries and staining were generally perceived as being significantly less favourable than TF6, with higher need to seek correction as well. Noncavitated carious lesion and incisal chip were rated similar to TF0. Cavitated carious lesions were rated aesthetically similar or significantly worse than TF0 and TF6. CONCLUSIONS Severe fluorosis (TF5 and 6) was perceived to be less aesthetically pleasing and received higher ratings for need to seek correction than normal teeth. Mild-to-moderate fluorosis (TF1-4) showed similar or better aesthetic perceptions and similar or lower need to seek correction, when compared to normal teeth (TF0). Easily visible cavitated dental caries was rated worse than teeth with severe fluorosis (TF6) and normal teeth (TF0).

Differences in willingness to pay for an extraction, a filling, and cleaning teeth at various levels of oral health-related quality of life, as measured by oral impacts on daily performance, among older adults in Singapore

OBJECTIVE To examine the differences in Willingness to pay (WTP) for an extraction, a filling, and cleaning of teeth among older adults with varying levels of Oral Health-related Quality of Life (OHQoL). BACKGROUND OHQoL has been used extensively to measure utilities as reported by individuals of interest. Currently there are no reports that examine the WTP of individuals at various levels of OHQoL. METHODS A convenience sample of adults 60 years or older were recruited. Besides other domains, questionnaires were used to assess WTP (extraction, filling, and cleaning of teeth), OHQoL (using Oral Impacts on Daily Performance-OIDP), McArthur scale, and access to care. RESULTS Tamil ethnicity was related to higher WTP for an extraction (mean ratio, 1.63-3.98; 95% Confidence Interval [CI]), increase of age in years was related to lower WTP for extraction (mean ratio, 0.96-1.00 [95%CI]) and increasing OIDP score was related to lower WTP for extractions (mean ratio, 0.80-0.99 [95%CI]). Tamil ethnicity was associated with higher WTP for fillings (mean ratio, 2.69-6.44 [95%CI]); higher age in years was associated with lower WTP for fillings (mean ratio, 0.94-0.99 [95%CI]), and higher OIDP scores was trending to be associated to lower WTP for filling (mean ratio, 0.80-1.00 [95%CI]). Tamil Ethnicity was also associated with higher WTP for cleaning (mean ratio, 2.14-7.19 [95%CI]), higher age in years was also associated with cleaning (mean ratio, 0.94-0.99 [95%CI]). CONCLUSION Individuals with higher OIDP scores tended to have lower WTP for extraction, filling and cleaning; with significant differences reported for extraction.